1. Field
Various embodiments described herein relate to a management program embodied in a computer readable medium, a management apparatus, and a management method for managing a storage system via a network.
2. Description of the Related Art
Currently, data processing using computers is being widely practiced, resulting in a greater significance being attached to storage technology for saving and utilizing data. In recent years, distributed storage systems are being constructed with the intention of increasing reliability when saving data and enabling data to be utilized at higher rates.
In a distributed storage system, a plurality of storage nodes and access nodes are connected via a network. A storage node includes a storage device and stores data. An access node accesses data stored in a storage node. An access node is capable of distributing and storing data across a plurality of storage nodes. Accordingly, load is distributed across a plurality of storage nodes and the speed of the system may be increased. In addition, an access node is capable of increasing the redundancy of data and allocating the data across a plurality of storage nodes. Accordingly, the reliability of data saving may be increased.
Moreover, in a distributed storage system, a single logical storage area (logical volume) may be set so as to straddle storage devices of a plurality of storage nodes. A plurality of logical volumes may be set, whereby, for example, a different logical volume may be used for each different service to be provided. Such an arrangement enables a plurality of services to enjoy the benefits of a distributed storage system.
Meanwhile, in system operation and management, monitoring is performed on loads generated at nodes making up the system. Load monitoring enables identification of nodes vulnerable to load concentration and nodes having unused processing capacity. Based on the result of such identification, tuning of the overall system, expansion of hardware resources, addition of functions, and the like may be performed in an appropriate manner depending on the usage of the respective nodes.
Load monitoring is also performed in distributed storage systems. In particular, at a storage node, monitoring the load on a storage device is important due to frequent reading/writing of data. Conceivable monitoring objects include storage area utilization (used amount). By monitoring storage area utilization, the occurrence of a shortage in a storage area may be prevented. For example, when used capacity exceeds a predetermined level at a specific storage node, it is conceivable that the data stored in the storage node in question be relocated to a storage node with spare storage area to equalize the used capacities of the respective storage nodes (Japanese Patent Laid-Open No. 2005-050303).
Another conceivable monitoring object is, for example, logical volume-specific utilization. By monitoring logical volume-specific utilization in each storage node, for example, service-specific usage can be known (Japanese Patent Laid-Open No. 2003-296039).